We don't need meat any more, it's the reason why heart related illnesses are the number one killer in western society and the reason why we are having higher rate of obese people every year, it's because people still continue to eat meat without exercising, 'but' what people don't get is that most of these people over indulging themselves on meat wouldn't be over weight in the first place if they eat a healthy vegetarian diet, and therefore wouldn't need to 'actively' do any extra exercise beyond their normal every day activities, people need to match their diet around their lifestyle.
People are still eating a diet that is from the stone age, in that age it made sense to eat meat as we were hunter gatherers and needed to, today people are consuming a stone age diet while doing a 9-5 office job, it's just not required any more beyond for-filling our taste buds.
And on top of that the meat industry is thee most environmentally destructive industry on the planet, the only thing it's really good for is putting people in jobs and making money (which isn't all bad of course).
A do agree with Nitely, it would be hard to dissolve the meat industries but I think it could be done over time, and tbh I think it will happen naturally as a part of our evolutionary process anyway, but at a lower rate of change.